EXHAUSTION OF THE CURVE GRAPH VIA RIGID EXPANSIONS

2018 ◽  
Vol 61 (1) ◽  
pp. 195-230 ◽  
Author(s):  
JESÚS HERNÁNDEZ HERNÁNDEZ
Keyword(s):  
Topological Type ◽  
Orientable Surface ◽  
Finite Topological Type ◽  
Curve Graph ◽  
Finite Set ◽  
Rigid Set

AbstractFor an orientable surfaceSof finite topological type with genusg≥ 3, we construct a finite set of curves whose union of iterated rigid expansions is the curve graph$\mathcal{C}$(S). The set constructed, and the method of rigid expansion, are closely related to Aramayona and Leiniger's finite rigid set in Aramayona and Leininger,J. Topology Anal.5(2) (2013), 183–203 and Aramayona and Leininger,Pac. J. Math.282(2) (2016), 257–283, and in fact a consequence of our proof is that Aramayona and Leininger's set also exhausts the curve graph via rigid expansions.

scholarly journals FINITE RIGID SETS IN CURVE COMPLEXES

2013 ◽  
Vol 05 (02) ◽  
pp. 183-203 ◽  
Author(s):  
JAVIER ARAMAYONA ◽  
CHRISTOPHER J. LEININGER
Keyword(s):  
Class Group ◽  
Topological Type ◽  
Orientable Surface ◽  
Mapping Class ◽  
Curve Complex ◽  
Finite Topological Type ◽  
Punctured Torus ◽  
Curve Complexes ◽  
Simplicial Map ◽  
Pointwise Stabilizer

We prove that curve complexes of surfaces are finitely rigid: for every orientable surface S of finite topological type, we identify a finite subcomplex 𝔛 of the curve complex [Formula: see text] such that every locally injective simplicial map [Formula: see text] is the restriction of an element of [Formula: see text], unique up to the (finite) pointwise stabilizer of 𝔛 in [Formula: see text]. Furthermore, if S is not a twice-punctured torus, then we can replace [Formula: see text] in this statement with the extended mapping class group Mod ±(S).

scholarly journals On manifolds with quadratic curvature decay

2009 ◽  
Vol 145 (2) ◽  
pp. 528-540 ◽  
Author(s):  
Nader Yeganefar
Keyword(s):  
Topological Type ◽  
Noncompact Manifold ◽  
Asymptotic Cones ◽  
Finite Topological Type ◽  
Curvature Decay

AbstractWe give conditions which imply that a complete noncompact manifold with quadratic curvature decay has finite topological type. In particular, we find links between the topology of a manifold with quadratic curvature decay and some properties of the asymptotic cones of such a manifold.

On the homeotopy group of a non-orientable surface

1972 ◽  
Vol 71 (3) ◽  
pp. 437-448 ◽  
Author(s):  
Joan S. Birman ◽  
D. R. J. Chillingworth
Keyword(s):  
Projective Planes ◽  
Double Cover ◽  
Orientable Surface ◽  
Factor Group ◽  
Simple Type ◽  
Defining Relations ◽  
Entire Structure ◽  
Finite Set ◽  
Orientable Surfaces ◽  
Made In

Let X be a closed, compact connected 2-manifold (a surface), which we will denote by O or N if we wish to stress that X is orientable or non-orientable. Let G(X) denote the group of all homeomorphisms X → X, D(X) the normal subgroup of homeomorphisms isotopic to the identity, and H(X) the factor group G(X)/D(X), i.e. the homeotopy group of X. The problem of determining generators for H(O) was considered by Lickorish in (7, 8), and the second of these papers specifies a finite set of generators of a particularly simple type. In (10) and (11) Lickorish considered the analogous problem for non-orientable surfaces, and, using Lickorish's partial results, Chilling-worth (4) determined a finite set of generators for H(N). While the generators obtained for H(O) and H(N) were strikingly similar, it was noteworthy that the techniques used in the two cases were different, and in particular that little use was made in the non-orientable case of the earlier results obtained on the orientable case. The purpose of this note is to show that the results of Lickorish and Chillingworth on non-orientable surfaces follow rather easily from the work in (7, 8) by an application of some ideas from the theory of covering spaces (2). Moreover, while Lickorish and Chillingworth sought only to find generators, we are able to show (Theorem 1) how in fact the entire structure of the group H(N) is determined by H(O), where O is an orientable double cover of N. Finally, we are able to determine defining relations for H(N) for the case where N is the connected sum of 3 projective planes (Theorem 3).

scholarly journals Complete gradient shrinking Ricci solitons have finite topological type

2008 ◽  
Vol 346 (11-12) ◽  
pp. 653-656 ◽  
Author(s):  
Fu-quan Fang ◽  
Jian-wen Man ◽  
Zhen-lei Zhang
Keyword(s):  
Topological Type ◽  
Ricci Solitons ◽  
Finite Topological Type

A finite set of generators for the homeotopy group of a non-orientable surface

1969 ◽  
Vol 65 (2) ◽  
pp. 409-430 ◽  
Author(s):  
D. R. J. Chillingworth
Keyword(s):  
Normal Subgroup ◽  
Quotient Group ◽  
Closed Surface ◽  
Orientable Surface ◽  
Finite Set

Let X be a closed surface, i.e. a compact connected 2-manifold without boundary. If Gx denotes the group of all homeomorphisms of X to itself, and Nx is the normal subgroup consisting of homeomorphisms which are isotopic to the identity, then the quotient group Gx/Nx is called the homeotopy group of X and is denoted by ∧x.

scholarly journals Counting unicellular maps on non-orientable surfaces

2010 ◽  
Vol DMTCS Proceedings vol. AN,... (Proceedings) ◽  
Author(s):  
Olivier Bernardi ◽  
Guillaume Chapuy
Keyword(s):  
Connected Graph ◽  
Topological Type ◽  
Orientable Surface ◽  
Recurrence Equation ◽  
Asymptotic Formulas ◽  
Topological Disk ◽  
International Audience ◽  
Fixed Topology ◽  
Orientable Surfaces

International audience A unicellular map is the embedding of a connected graph in a surface in such a way that the complement of the graph is a topological disk. In this paper we give a bijective operation that relates unicellular maps on a non-orientable surface to unicellular maps of a lower topological type, with distinguished vertices. From that we obtain a recurrence equation that leads to (new) explicit counting formulas for non-orientable precubic (all vertices of degree 1 or 3) unicellular maps of fixed topology. We also determine asymptotic formulas for the number of all unicellular maps of fixed topology, when the number of edges goes to infinity. Our strategy is inspired by recent results obtained for the orientable case [Chapuy, PTRF 2010], but significant novelties are introduced: in particular we construct an involution which, in some sense, ``averages'' the effects of non-orientability. \par Une carte unicellulaire est le plongement d'un graphe connexe dans une surface, tel que le complémentaire du graphe est un disque topologique. On décrit une opération bijective qui relie les cartes unicellulaires sur une surface non-orientable aux cartes unicellulaires de type topologique inférieur, avec des sommets marqués. On en déduit une récurrence qui conduit à de (nouvelles) formules closes d'énumération pour les cartes unicellulaires précubiques (sommets de degré 1 ou 3) de topologie fixée. On obtient aussi des formules asymptotiques pour le nombre total de cartes unicellulaires de topologie fixée, quand le nombre d'arêtes tend vers l'infini. Notre stratégie est motivée par de récents résultats dans le cas orientable [Chapuy, PTRF, 2010], mais d'importantes nouveautés sont introduites: en particulier, on construit une involution qui, en un certain sens, "moyenne'' les effets de la non-orientabilité.

Circle patterns on surfaces of finite topological type revisited

2020 ◽  
Vol 306 (1) ◽  
pp. 203-220
Author(s):  
Yue-Ping Jiang ◽  
QiangHua Luo ◽  
Ze Zhou
Keyword(s):  
Topological Type ◽  
Finite Topological Type ◽  
Circle Patterns

On Manifolds with Lower Quadratic Curvature Decay and Volume Pinching

2018 ◽  
Vol 2020 (21) ◽  
pp. 7857-7872
Author(s):  
Xiaosong Kang ◽  
Xu Xu ◽  
Dunmu Zhang
Keyword(s):  
Riemannian Manifold ◽  
Topological Type ◽  
Finite Topological Type ◽  
Noncompact Riemannian Manifold ◽  
Curvature Decay

Abstract We give some conditions for a complete noncompact Riemannian manifold with lower quadratic curvature decay to have finite topological type. Most of our curvature conditions are much weaker than the assumptions in Lott [5] and in Sha–Shen [10], hence our results can be viewed as natural generalizations of those works.

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